The present invention relates to an apparatus for inspecting and ascertaining the relative disposition of the rollers in dual roller and support tracks provided for withdrawing continuous castings along a curved path. U.S. Pat. No. 4,148,145 Ser. No. 827,614, filed Aug. 25, 1977 discloses a device in which a parallelogram-like collapsible frame is passed through the tracks by means of a cable, chain or the like, and which is provided on two opposite corners with centering rollers to engage two oppositely located track rollers. Feelers determine the distance between these two track rollers, and the frame is passed along the tracks to ascertain this way the effective width between the roller tracks as defined by the spacing of rollers being located opposite to each other, and to determine particularly any unwanted deviation from the required width.
The U.S. Pat. No. 4,132,003 Ser. No. 827,570 filed Aug. 25, 1977 uses a basically similar type of frame, but is provided with a different set of feelers to measure the effective curvature of the casting path as between the two tracks.
The present invention relates particularly to equipment of the type of those two patents and includes particularly such a foldable frame, centering rollers on two corners for engaging two opposite track rollers.